This invention relates to grain stirring devices and more particularly to a carriage return apparatus for coordinated reciprocal movement of multiple stirrers along the shaft of a grain stirring device to improve stirring coverage and therefore drying of the grain. The apparatus of this invention effectively eliminates the unstirred regions left between a plurality of adjacent stirrers.
Various known devices exist for stirring grain. U.S. Pat. No. 4,854,719, which issued Aug. 8, 1989, discloses a grain stirring device having a single, powered, auger-like stirrer supported on a carrier that is reciprocally movable longitudinally along a rotating shaft. The shaft is supported on one or more rails and moves in a direction generally transverse to the movement of the carrier when the shaft is rotated. A drive bearing or roller on the carrier frictionally engages the shaft. The roller is supported on a support member mounted on the carrier and is adaptable for shiftable pivotal movement about a fixed shift axis between two positions.
In one position, the roller is pivoted so its axis of rotation is at a positive angle with respect to the longitudinal axis of the shaft. When the shaft rotates, the roller rolls a helical path thereon, which causes the carrier to advance longitudinally in one direction. In another position, the roller is pivoted so its axis of rotation is at a negative angle with respect to the longitudinal axis of the shaft. The helical path and carrier advances longitudinally in the other direction. This basic device can be applied to grain bins of various shapes, including rectangular and circular.
A plurality of stirrers, mounted on respective carriers, can be made to operate on one shaft by interposing circular plates between them as disclosed in U.S. Pat. No. 4,836,686, which issued Jun. 6, 1989. However, a region of unstirred grain results below the circular plate interposed between the adjacent stirrers.
Therefore, a primary object of this invention is the provision of a carriage return apparatus for a grain stirring device that eliminates unstirred regions between adjacent stirrers.
A further object of the present invention is the provision of a carriage return apparatus for a grain stirring device that improves the stirring coverage obtained in a grain bin.
A further object of the present invention is the provision of a carriage return apparatus that allows the travel of adjacent stirrers along the shaft to be overlapped so as to improve stirring coverage.
A further object of the present invention is the provision of a grain stirring apparatus which is durable and reliable in use, and is economical to manufacture.
This invention contemplates other objects, features and advantages which will become more fully apparent from the following detailed description taken in conjunction with the accompanying drawings.